Preflight tests are conducted on aircraft engine subsystems prior to takeoff to verify their operation. An example of such a subsystem includes the inlet guide vanes control subsystem including the associated controller and actuator therefore.
Conventionally, preflight tests are performed to exercise the subsystem under predetermined conditions to ensure the subsystem's proper functionality for flight conditions. In such tests, the subsystem performance is monitored by various diagnostics and/or by a human observer on the ground and the pilot. Tests are typically conducted in sequence, which results in an increased pilot workload and increased aircraft ground time. For obvious reasons, both of these results translate into higher operational costs of the aircraft and specifically the aircraft engine.
More specifically, for some modern aircraft, the inlet guide vane control system (IGVCS) has a dual lane architecture comprised of an electronic primary lane an a hydro-mechanical secondary lane. The hydro-mechanical secondary lane serves as a back-up in the event of an electronic primary lane failure. The IGVCS controls the inlet guide vane position as a function of engine speed adjusted for air inlet temperature.
The primary electronic and secondary hydro-mechanical lanes have similar characteristics and each lane's characteristics must be verified individually before takeoff to ensure a fully operational system for a successful flight. The backup hydro-mechanical system control functionality is tested on power up by the pilot, in conjunction with the primary lane processor, by conducting a preflight test which ensures the hydro-mechanical lane's full operational capability. The current method requires significant input by the pilot.
There exists a need, therefore, for an actuator control test system, which test system is independent of operator intervention.